Abstract

Some pharmaceutical compounds namely valsartan, hydrocholorothiazide, erythromycin thiocynate and diclofenac potassium were studied as chemical additions for enhancing the finished C-steel surface attained. Anode potential–limiting current relationship was measured and comparing of gradually increasing pharmaceutical compound concentrations (1 × 10^–4–7 × 10^–4 M) and weight loss method. C‑steel dissolution behavior in presence of pharmaceutical compounds was studied under natural convection and (rotating cylinder (RCE) and rotating disc electrode (RDE) as forced convection. The rotation speed of RCE and RDE was studied. The limiting current was found to diminishes with enlarging additives concentration and increase with increasing temperature (293–313 K). Activation energies values confirm that reaction rate was diffusion controlled. Results showed that the improvement produced in electropolishing in presence of pharmaceutical compounds occurs through adsorption of their molecules above metal surface. Pharmaceutical compound adsorption obey kinetic–thermodynamic model. Retardation percentage obtained from weight loss measurement are comparable with those obtained from galvanostatic polarization measurements. The data under different conditions were controlled by dimensionless correlations Sherwood (Sh), Schmidt (Sc) and Reynolds (Re) numbers. Surface morphology study confirmed that addition of pharmaceutical compound to C-steel dissolution bath enhance surface appearance and its texture quality to great extent.

中文翻译：

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正常和强制对流情况下某些药物对H 3 PO 4酸中C-钢的电抛光作用

摘要

研究了一些药物化合物，如缬沙坦，氢氯噻嗪，红霉素硫氰酸盐和双氯芬酸钾作为化学添加剂，以增强最终的C型钢表面。测量了阳极电势限制电流的关系，并比较了逐渐增加的药物化合物浓度（1×10 ^–4 –7×10 ^–4M）和减肥方法。研究了在自然对流和（强制旋转）旋转圆柱（RCE）和旋转圆盘电极（RDE）下C-钢在药物对流下的溶解行为，研究了RCE和RDE的旋转速度，发现极限电流减小结果表明，在存在药物化合物的情况下，电抛光产生的改善是通过其分子在金属表面的吸附而实现的，活化能值证实了反应速率是受扩散控制的。药物化合物的吸附服从动力学-热力学模型。从重量损失测量获得的延迟百分率与从恒电流极化测量获得的延迟百分率相当。通过无量纲相关舍伍德（Sh），施密特（Sc）和雷诺（Re）数控制不同条件下的数据。表面形态学研究证实，向C型钢溶解浴中添加药物化合物可在很大程度上改善表面外观和质地质量。